Electrode

Patent metadata

Field	Value
Publication number	US-2024304816-A1
Application number	US-202218274700-A
Country	US
Kind code	A1
Filing date	Jan 28, 2022
Priority date	Jan 29, 2021
Publication date	Sep 12, 2024
Grant date	—

Abstract

The present application relates to an electrode comprising a current collector and an active material layer, which can provide an electrode capable of securing high levels of inter-particle adhesion force and adhesion force between the active material layer and the current collector relative to the binder content in the active material layer. Through this, it is also possible to provide a secondary battery having excellent performance, and the like, while having a high capacity.

First claim

1 . An electrode, comprising:
a current collector; and an active material layer on one or both sides of the current collector, wherein the active material layer comprises an electrode active material and a binder, wherein, after a standard peel test, a ratio of an area occupied by the binder on a predetermined area of the current collector to the predetermined area along one direction on the current collector shows a wave graph, and wherein the standard peel test: is a process of attaching a tape on the active material layer and then peeling off the tape from the active material layer, which is repeated until no component of the active material layer is observed on the tape.

2 . The electrode according to claim 1 , wherein the ratio is 55% or more at a crest portion of the wave graph.

3 . The electrode according to claim 1 , wherein the ratio is 50% or less at a valley portion of the wave graph.

4 . The electrode according to claim 1 , wherein a wavelength of the wave graph is from 3 nm to 25 mm.

5 . The electrode according to claim 1 , wherein a difference between a maximum value of the ratio in the wave graph and a minimum value of the ratio in the wave graph is 9% p or more.

6 . The electrode according to claim 1 , wherein the electrode comprises a region which satisfies Equation 1 and the ratio of 60% or more on the current collector after the standard peel test:
18≤ A/W    [Equation 1]
wherein A is a ratio (unit: %) of an area occupied by the binder on the current collector and W is a content (weight %) of the binder in the active material layer.

7 . The electrode according to claim 1 , wherein the binder is a particulate binder.

8 . The electrode according to claim 1 , wherein both of the electrode active material and the binder are in the forms of particles, and wherein a ratio (D1/D2) of an average particle diameter (D1) of the electrode active material to an average particle diameter (D2) of the binder is from 10 to 1000.

9 . The electrode according to claim 1 , wherein the binder is a particulate binder having an average particle diameter in a range of 50 nm to 500 nm.

10 . The electrode according to claim 1 , wherein the electrode active material is a particulate material having an average particle diameter in a range of 1 μm to 100 μm.

11 . The electrode according to claim 1 , wherein a ratio of the binder in the active material layer is from 0.5 weight % to 10 weight %.

12 . The electrode according to claim 1 , wherein the electrode active material is comprised in an amount of 1000 to 10000 parts by weight relative to 100 parts by weight of the binder.

13 . A method for manufacturing the electrode of claim 1 , comprising:
forming a layer of a slurry on the current collector, wherein the slurry comprises a solvent, the binder having a solubility parameter in a range of 10 to 30 MPa 1/2 and the electrode active material, and wherein the current collector surface on which the layer of the slurry is formed has a surface energy of 40 mN/m or more.

14 . An electrochemical element, comprising:
the electrode of claim 1 as a negative electrode or a positive electrode.

15 . A secondary battery, comprising:
the electrode of claim 1 as a negative electrode or a positive electrode.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Geun Sung
• Lee Il Ha
• Song In Taek
• Park Jin Woo
• Kim Ki Hwan
• Lee Ho Chan
• Hahm Yun Hye

Classifications

• H01M4/64

  Carriers or collectors · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/052

  Li-accumulators · CPC title